This invention relates to a method of making shoe and particularly a method that uses multiple material to form shoe integrally.
A conventional shoe generally includes an outsole 1, a lower sole 2, and a midsole 3 and other parts. The fabrication method of shoe generally includes the steps of: forming individual parts by injection molding process, manually coating adhesive (such as a strong bonding adhesive) on the contact surfaces, using a compression machine to compress the bonding parts, adhering the parts through the adhesive, and stitching a vamp (4) to the sole to form the finished shoe. It is a lengthy and tedious process (such as shown in FIG. 1). Moreover the shoes being made are prone to fall apart or rupture. In order to improve shoe quality, some shoe producers use rubber which has better wearing resistance and anti-slippery property to make the outsole (1) and Thermo Plastic Poly Urethane (TPU) which has excellent elastic tensile strength to make the lower sole (2). However up to present, there is still no technique available for bonding the rubber and TPU as they have a lot of different material characteristics. This becomes a big problem to the shoe producers.
How to develop a method for bonding rubber and TPU so that the outsole (1), lower sole (2), midsole (3) and vamp (4) may be integrally formed for saving time and cost is one of the critical issues in the shoe industry.
It is therefore an object of this invention to provide a method for integrally forming the outsole, lower sole, midsole and vamp thereby to save production cost and time.
Another object of this invention is to use a coupling agent for bonding the outsole made from rubber and lower sole made from TPU thereby to produce a shoe that has greater wearing resistance, anti-slippery and elastic tensile strength.
To attain aforesaid objects, the method of this invention employs mating molds which have a lower cavity and a middle cavity. The fabrication process includes the steps of blending, melting and injecting, secondary injecting, positioning and pouring. And a coupling agent is added to complete the process.
By means of aforesaid process, when the TPU is being injected, the bottom contact surface of the sole is slightly melted for bonding the TPU and the sole made from the rubber, then the vamp is disposed over the midsole and PU is poured onto the vamp to form the midsole, thereby the vamp is integrally formed with the midsole, lower sole and outsole.